WASHINGTON — A midterm campaign that has turned heavily on the issue of the mounting federal debt is likely to yield a government even more split over what to do about it, people in both parties say, with diminished Democrats and reinforced Republicans confronting internal divisions even as they dig in against the other side.

In the weeks after the Nov. 2 elections, the White House and a lame-duck Congress will face immediate decisions testing the balance of power — on extending the Bush-era tax rates, approving overdue spending bills to keep the government operating and, possibly, debating the recommendations that President Barack Obama has directed a bipartisan debt-reduction commission to offer by December.

The report of the 18-member commission, which includes a dozen senior members of Congress, six from each party, will help determine whether a bipartisan consensus exists to deal with the unsustainable combination of fast-growing entitlement programs like Social Security and Medicare and inadequate tax revenues.

The group has delayed making decisions until after the election, to avoid leaks that would become campaign fodder, but even some of its members doubt they can muster the 14 votes needed to send a package to Congress for a vote; at best they hope options left on the table, or agreed to by the chairmen — Erskine Bowles, a White House chief of staff to President Bill Clinton, and Alan Simpson, the former Republican Senate leader from Wyoming — will find support in the spending-and-tax debates.

In interviews, a number of Democrats and Republicans agreed on one thing: For all the pre-election talk that a divided government could force the parties to work together, especially on cutting annual deficits, the opposite could just as well be true.